Multi-response vibration damper assembly

Abstract

A damper assembly system that can provide for multiple frequency responses to control Aeolian vibration in EHV (Extra High Voltage) applications is disclosed. The damper assembly comprises an asymmetric design that enables two disparate frequency responses at either side of the clamp that attaches the damper to a suspended member or cable. Two additional frequency responses are enabled at an inlet point of each of the damper weights. The damper weights can have a rounded or egg-shape together with an inner cavity so as to control corona discharge in EHV applications. Additionally, the tuned weights can be of disparate mass as well as asymmetric distances from the clamp.

1 . An apparatus that suppresses wind-induced vibrations on a cable, comprising:
 a messenger having a first and second termination end;   a first weight fixedly attached to the first termination end;   a second weight fixedly attached to the second termination end; and   an attachment means asymmetrically positioned between the first and second weights, wherein the attachment means connects the apparatus to the cable and enables the apparatus to responds to at least four disparate resonant frequencies.   
     
     
         2 . The apparatus of  claim 1 , wherein the first weight and the second weight are rated for applications upon suspended transmission lines in excess of 230 kilovolts (Kv). 
     
     
         3 . The apparatus of  claim 1 , wherein the first weight has a first mass and wherein the second weight has a greater mass than the first mass. 
     
     
         4 . The apparatus of  claim 1 , the first weight and the second weight comprise a substantially rounded outer shell having an inlet portion that accepts an end of the messenger; wherein the substantially rounded outer shell controls corona discharge in an Extra High Voltage (EHV) application. 
     
     
         5 . The apparatus of  claim 4 , at least one of the first weight or the second weight comprise a mass distribution that enables oscillation about a center of gravity of about the at least one of the first weight or the second weight, wherein the oscillation enables response to vibration frequency. 
     
     
         6 . The apparatus of  claim 1 , wherein the attachment means comprises a “hanger-shaped” apparatus having a plurality of grooves on the outward facing portion of the “hanger-shaped” apparatus, wherein the grooves retain a plurality of helical windings that secure the apparatus to the cable. 
     
     
         7 . The apparatus of  claim 6 , further comprising an insert that cushions the connection between the attachment means and the cable. 
     
     
         8 . The apparatus of  claim 7 , wherein the insert is an elastomeric insert. 
     
     
         9 . The apparatus of  claim 1 , wherein two of the at least four disparate frequency responses occur when vibration is distal to the attachment means for each of the first weight and the second weight. 
     
     
         10 . The apparatus of  claim 9 , wherein two of the at least four disparate frequency responses occur upon oscillation of at least the first weight or the second weight about its center of gravity. 
     
     
         11 . The apparatus of  claim 1 , wherein the messenger is a stranded cable messenger. 
     
     
         12 . The apparatus of  claim 11 , wherein the first weight and the second weight are attached to the messenger using a crimp- or collet-type attachment means. 
     
     
         13 . The apparatus of  claim 11 , wherein the first weight and the second weight are attached to the messenger using a staking ball attachment means. 
     
     
         14 . A dampening system, comprising:
 a messenger cable having a fixed length;   a first substantially egg-shaped weight attached to a first end of the messenger cable, wherein the first substantially egg-shaped weight oscillates about its center of gravity; and   a second substantially egg-shaped weight having a mass greater than the first substantially egg-shaped weight and attached to a second end of the messenger cable, wherein the second substantially egg-shaped weight oscillates about its center of gravity.   
     
     
         15 . The dampening system of  claim 14 , further comprising a clamp positioned asymmetrically between the first and second substantially egg-shaped weights, wherein the dampening system is capable of at least four response frequencies. 
     
     
         16 . The damping system of  claim 14 , wherein the first and second substantially egg-shaped weights are EHV rated to control corona discharge. 
     
     
         17 . The dampening system of  claim 14 , wherein each of the first and second substantially egg-shaped weights comprises an inner cavity having a skirt that provides for EHV corona discharge control. 
     
     
         18 . A method of configuring a damper assembly, comprising:
 attaching a first EHV-rated weight to one end of a messenger;   attaching a second EHV-rated weight to an opposite end of the messenger; and   asymmetrically positioning a clamp between the first weight and the second weight upon the messenger, wherein the clamp enables attachment to a cable under tension, and wherein the damper assembly facilitates response to a plurality of frequencies of vibration associated with the cable under tension.   
     
     
         19 . The method of  claim 18 , wherein the first weight and the second weight have unequal masses. 
     
     
         20 . The method of  claim 18 , further comprising wrapping a plurality of helical windings about the clamp, wherein the helical windings secure the clamp to the cable under tension.